Abstract: In order to study the trigger breakdown characteristics of the fast pulsed linear transformer driver (FLTD) multi-gap gas switch, a two-gap equivalent gas switch was studied under different trigger voltages, working coefficients and electrode materials. The delay and jitter of the trigger gap and overvoltage gap were gained, and the main factors affecting the breakdown characteristics were analyzed. The experimental results show that the delay of the trigger gap is mainly influenced by trigger voltage, and the delay of the overvoltage gap is mainly influenced by working coefficient. The jitter of the switch mainly comes from the trigger gap. The jitter of trigger gap decreases with the increase of the trigger voltage, while the jitter of overvoltage gap is not affected by trigger voltage and working coefficient and maintains at a low value. The switch with graphite electrode has better trigger characteristics and lower delay and jitter. Preionization may be the main reason for the different breakdown characteristics of the two gaps.